This proposal concerns interleukin-1 (IL-1) as a key mediator of host responses to microbial invasion, inflammation, immunological reaction and injury. IL-1 is one of the first and most prominent molecular synthesized following the onset of infection or injury. Many of IL-1's effects are involved with pathological processes, and the host has mechanisms by which synthesis, processing, transport and activities of IL-1 are regulated. This proposal studies these various mechanisms. The experiments are designed to explore IL-1 production from human blood monocytes. Up to 5% of the total polyadenylated RNA codes for IL-1-beta in monocytes after stimulation. Mechanisms control the translation of this RNA into IL-1 protein whereas other mechanisms seem to control processing of the primary translation product into biologically active IL-1. Transcription, translation and processing of IL-1 are different in blood monocytes than in cultured cells lines. Therefore, these experiments are focused on each of the steps of IL-1 production in circulating human blood cells in health, in disease and under the influence of various disease modifying substances. special methods will be employed that prevent the transcription of Il-1 in monocytes due to adherence to surfaces. Two newly developed radioimmunoassays for IL-1-beta and Il-1- alpha will be used in a large study to establish what constitutes "normal" Il-1 production. Immunoprecipitation and immunofluorescence using specific, non-cross reacting antibodies will be used to detect the sizes and cellular localization of IL-1. The specific biological activities of Il-1 differ with the molecular size and hence studies on the structure-function relationship of IL-1 are proposed in order to identify a putative active site(s). The evaluation of synthetic peptides will be performed and correlated with naturally occurring fragments of monocyte Il-1. An animal model of hemodynamic shock using toxic shock syndrome toxin is to be used to evaluate the systemic effects of Il-1, its fragments and substances that inhibit its biological activities. Two clinical models will be used to study Il-1 production in human subjects: the effect of supplemental fish oil diet and hemodialysis. These studies complement the basic investigations on the molecular control of IL-1 production. Finally, these studies examine the production and activity of IL-1 in models of endogenous amplification and inhibition.